Forschungs- & Entwicklungsinformationsdienst der Gemeinschaft - CORDIS


TECHNI Berichtzusammenfassung

Project ID: HPRI-CT-1999-50005
Gefördert unter: FP5-HUMAN POTENTIAL
Land: Germany

Correction elements for highest resolution in neutron scattering technique

A new low gamma-sensitive image plate detector has been developed. A new approach to the construction of image plate detectors of medium resolution (of about 1 mm), which fits to requirements of neutron scattering, was suggested.

Different storage phosphors and neutron converters have been tested to find an appropriate mixture for the neutron image plate with low gamma-sensitivity. It was observed for the first time that the mixture KX:Eu(2+) (X=Cl, Br) (storage phosphor) and 6LiF (neutron converter) is a very attractive detector materials to be used in a high gamma-background environment. Calculations and measurements were performed to optimise the image plate parameters. The main processes that affect image plate detector performance were investigated and a mathematical model was developed.

Experimental tests for preparations of such pixelated neutron image plates were carried out. First test experiments were performed at a neutron beam port at the reactor DIDO at the FZ Julich. Discussions with TU Delft on Gd nano-particles resulted in a change to 6Li, which is much more attractive from the point of view of neutron sensitivity and gamma-ray insensitivity. It was shown, that optimal size of the absorbing 6Li particles is about 40 µm, the optimal size of the storage phosphor is about 10µm. MCNP calculations have been performed to study the problem of the light propagation in the image plate aiming to find optimal conditions (reflecting walls and bottom) for high effective read-out process.

A prototype of the scanner with the high light collection efficiency was constructed and tested; the test neutron images have been scanned and parameters of the scanner have been preliminary defined.

An optimisation of parameters of the pixelated image plate was carried out. MCNP calculations have been performed to estimate the expected resolution and efficiency as a function of the pixel parameters and wall coatings. A prototype of pixelated image plate with pixel size of 1 x 1mm{2} was prepared and successfully tested at the neutron beam. The first large scale, 100 x 100mm{2}, image plate was produced. The laser image plate scanner with the high light collection efficiency was constructed and the optical system and the control software were tested. The optical scanning system shows the resolution better than 0.03mm.


Alexander IOFFE, (Scientist)
Tel.: +49-2461613826
Fax: +49-246-1612610
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